Method and apparatus for programming programmable controllers and providing version management from a centralized server

ABSTRACT

A method and system for generating programming code and/or configuration data for programmable controller and the networks on which they operate is disclosed. In one embodiment, programming code is generated on a centralized server having a web-enabled engineering tool. The engineering tool operates on client devices that are in communication with the server over a network, such as the Internet. Preferably, the engineering tool runs in a browser application (or other network-interfacing-application) on the client device and a user generates the programming code on the server with the aid of the client device. By centralizing the engineering tool, which may contain a configuration editor and a configuration management tool having version management functionality, a new business paradigm for providing engineering tool services to customers having programmable controllers. In addition, new methods and tools for collaborative engineering of programming code are enabled.

The present application is a divisional patent application of patentapplication Ser. No. 09/961,931 filed on Sep. 24, 2001, of Lo for“Method and Apparatus for Programming Programmable Controllers andGenerating Configuration Data from a Centralized Server”.

FIELD OF THE INVENTION

The present invention relates generally to the field of programmablecontrollers. In particular, the present invention provides an apparatusand methods for writing programming code and/or generating configurationdata for these programmable controllers without the need to purchase andinstall an engineering tool on a programming device.

BACKGROUND OF THE INVENTION

Programmable controllers, including Programmable Logic Controllers(“PLCs”) are used in many commercial and industrial applications.Programmable controllers typically monitor inputs, make decisions basedon how they are programmed, and control outputs of automated processesor machines. One of the most common programmable controllers in use isthe PLC. PLCs consist of input modules or points, a Central ProcessingUnit (“CPU”), and output modules or points. An input accepts a varietyof digital or analog signals from various field devices, such assensors, and converts them into a logic signal that can be used by theCPU. The CPU makes decisions and executes control instructions based onprogramming instructions stored in a memory. These programminginstructions determine what the PLC will do for a specific input. Outputmodules convert the control instructions from the CPU into a digital oranalog signal that can be used to control various field devices, such asactuators or valves.

Since most programmable controllers, including PLC's, are in essencecomputers, they store information in the form of On or Off conditions(i.e. 1 s or 0s), referred to as binary digits (i.e. bits). A programfor a programmable controller consists of one or more instructions thataccomplish a task. Programming a PLC or other controller is a matter ofconstructing a set of instructions. Programming usually also involvesgenerating configuration data. Configuring a programmable controllerinvolves mapping the controller's input/output)(“I/O”) area to thephysical I/O. Configuration editors are generally graphical.

There are several ways to look at a program, such as for example, flowchart programming, Ladder Logic, Instruction Lists, or Function BlockDiagrams. Ladder logic (“LAD”) is one programming language used withPLCs. As is shown in FIG. 1, Ladder Logic code 10 uses graphical symbolsthat resemble electromechanical elements used in a relay logic diagramformat to describe hard-wired control. The left vertical line of atypical Ladder Logic Diagram usually represents a power or energizedconductor. A right vertical line, represents the return path of ahard-wired control line diagram, and may be omitted. Ladder LogicDiagrams are read from left to right, top to bottom. Rungs are oftenreferred to as networks. A network may have several input and outputinstructions. Input instructions represented by a series of contacts, inone or more parallel branches, perform comparisons or tests, and arenormally left justified on the rung. Output instructions represented bycoils, for which there may only be one in each output branch, executesome operations or functions, and are normally right justified on therung. As is shown in the exemplary Ladder Logic code 10 depicted in FIG.1, I0.0, I0.1, and Q0.0 represent the first instruction combination. Ifinputs I0.0 and I0.1 are energized, output Q0.0 is energized. The inputscould be switches, pushbuttons, or contact closures. The output could,for example, be a solenoid or a light bulb. I0.4, I0.5 and Q0.1represent a second instruction combination. If either input I0.4 or I0.5are energized, output Q0.1 energizes.

An Instruction List (“IL”) provides another view of a set ofinstructions and is exemplified at 20 in FIG. 1. The operation, i.e.,what is to be done, is shown on the left. The operand, the item to beoperated on by the operation, is shown on the right. The LAD and the ILhave a similar structure. The set of instructions in the IL 20 of FIG. 1performs the same task as the LAD of 10.

Function Block Diagrams (“FBDs”) provide another view of a set ofinstructions and are exemplified at 30 in FIG. 1. Each function has aname to designate its specific task. Functions are indicated by arectangle. Inputs are shown on the left-hand side of the rectangle andoutputs are shown on the right-hand side. The Function Block Diagram 30shown in FIG. 3 performs the same tasks as shown by the LAD 10 of FIG. 1and the IL 20 of FIG. 1.

Programmable controllers in general, and PLCs in particular, executeprogram code in a repetitive process referred to as a scan. A scan maystart with the CPU reading a status of inputs. The application programis executed using the status of inputs. Once the program is complete,the CPU performs internal diagnostics and communication tasks. The scancycles ends by updating the outputs, then starts over. The cycle timedepends on the size of the program, the number of I/O's, and the amountof communication required.

In order to write programming instructions and generate configurationdata and download the code and configuration data to a programmablecontroller, several tools are needed. As is shown in FIG. 1, aprogramming device, such as a personal computer 1, is interfaced with aPLC 7. Typically, a proprietary cable 5, such as Siemens® PC/PPI,connects the computer's RS 232 port with the PLC 7. Prior to the presentinvention, engineering software tools 3, such as Siemens STEP 7,® had tobe installed on the PC so that the PC might be used to write programminginstructions for the PLC Typically, the engineering tools are sold onCD's or on another computer readable medium.

FIG. 2 outlines the typical steps and shortfalls that result from thepurchase of a copy of an engineering tool. The customer of anengineering tool typically buys a copy of the software and obtains alicense to use the tool, step 20. The customer must then install thesoftware on a single customer computer, step 25. The customer can onlydevelop application software, i.e. programming code for a programmablecontroller on computers that have the engineering tool, step 27. Thelicense agreements typically accompanying engineering tools restrict thecustomer's ability to install the tool on more than one computer withoutpaying for a license for any additional computers.

The software or engineering tools, such as Siemens STEP7® or MicroWin,®are often proprietary tools developed by the controller manufacturer.Typically, the development of these engineering tools takes thousands ofperson-hours. The tools are often designed and tested to work on aspecific computer operating system, such as for example MicrosoftWindows® 98. When the operating system for the computer on which thetool is used changes, the tool needs to be re-verified. Often, PCvendors deliver only the newest Microsoft operating system on their PCs.This forces the engineering tool vendors to also support the newoperating system, which usually means additional hundreds or thousandsmore person-hours of investment. In many organizations, the operatingsystem of the PC is updated without regard to the software, such as theengineering tools, residing on the PCs.

Engineering tools are often updated over time. Consequently, differentversion of the tools may exist at the same time. In a largemanufacturing facility it is likely that not all the programming toolsare using the same version. This not only increases the costs ofownership, but also can cause problems when different programmingdevices are used to write programming code for the same PLC application.Often, a team of engineers is assigned to program a PLC. Each engineerin the team may work independently on a discrete aspect of theapplication. At a later time, these various discrete aspects arecombined into one program that operates on the PLC. If the engineers arenot all using the same version of the tool, it is possible that the codegenerated from a version of the tool may not be compatible to an earlierversion of that tool.

In addition to problems associated with running different operatingsystems on the programming devices and different versions of theengineering tools on the operating systems, the programming code for theprogrammable controllers is often not archived in a centralized manner.Often the code for one PLC in a factory may be stored on one laptop ordesktop personal computer and the code for another PLC may be storedelsewhere. If a PLC were originally programmed with a first PC and thatPC is latter replaced with a second PC and if the PLC reprogrammed witha second PC, there often would be no way to restore the originalprogram, should the new program be deficient.

SUMMARY OF THE INVENTION

The present invention provides a system for programming a programmablecontroller, such as a PLC or other industrial controller. In oneembodiment, a client device having a network-interfacing-application,such as for example a browser application, communicates over a networkwith a server. An engineering tool for creating programming code andconfiguration data for programmable controllers resides on the server.The engineering tool employs a programming language for programmingprogrammable controllers and is accessible by the client device usingthe browser application residing thereon. The server may have anassociated storage unit for storing programming code generated by theengineering tool on the client device. In some embodiments, theengineering tool employs a graphical programming language, such asLadder Logic, Flowchart Programming, or Function Block Programming. Inother embodiments, it may employ text based languages, such asInstruction Lists. A compiler for compiling the programming code mayalso reside on the server or be accessible to the server.

Accordingly, the present invention provides for numerous and robustmethods for developing programming code for programmable controllers. Inone embodiment, a user accesses a server over a network with a clientdevice that has a browser application. The engineering tool ispreferably invokable by the browser application. The user then creates adocument containing programming instructions with the engineering tool.The document is then transmitted over the network to the server. Thedocument may be stored on the server for later access and editing. In aparticular embodiment, the document is an XML document.

In one embodiment of the present invention, programming code is storedon a central server. This provides a cost-effective and efficient methodfor programming programmable controllers. The server and theprogrammable controller may be interfaced to communicate with each otherover a network. After interfacing the two, compiled programming code maybe downloaded from the server to the controller over the network.

The present invention provides a new paradigm in the way entitiesapproach programming of their programmable controllers. Entities wishingto program their programmable controllers need not purchase and maintainexpensive engineering tools. Instead, an engineering tool may beweb-enabled and may be maintained on a central server that is accessibleover a computer network. Users having client devices are provided withaccess to the server over the network. The server receives from theclient device a document containing programming code created on theclient device with the engineering tool. The code may be compiled on theserver and downloaded to the programmable controller. It may bedownloaded directly to the controller, if the device is accessible overthe computer network, or it may be downloaded to the device through aclient device that resides on the network and that is interfaced withthe programmable controller.

The present invention also enables the generation of configuration datafor I/O networks and device on a centralized server. In general,development of programming code may comprise generating configurationdata. In one embodiment of the present invention a configuration editoris maintained on a server. The server is communicatively coupled to anetwork and the configuration editor is adapted to be invoked by aclient device over the network. The configuration editor may comprise agraphical editor, and it may be part of an engineering tool or be partof an engineering tool set.

The present invention also enables version management of variousversions of a program for a programmable controller. A versionmanagement tool is installed on a server. Along with the tool, variousversions of the program are stored. The version management tool isconfigured to be invokable by a client device over a network. Theversion management tool may have searching capabilities and functionsfor comparing one version with another to show changes between the two.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of the prior art tools required to programprogrammable controllers.

FIG. 2 is a block diagram illustrating the steps and shortcomings of theprior art methods and tools for programming programmable controllers.

FIG. 3 is an illustration of one embodiment of the present invention,wherein a client device that is connected to a PLC is in communicationover a network with a server containing a web-enabled engineering toolfor writing programming code for the PLC and for configuring the I/Onetwork and devices.

FIG. 4 is an illustration of the general architecture of one embodimentof the present invention, wherein an engineering tool for writingprogramming code for a programmable controller and for configuring theI/O network and devices resides on a server that is accessible over anetwork by a client device.

FIG. 5 illustrates an alternative embodiment of the present invention,wherein the server also contains a web service layer.

FIG. 6 illustrates, from both a client and server perspective, thecomponents of a web-enabled engineering tool according to the presentinvention that operates over the Internet, wherein chart-programmingtechniques are used.

FIG. 7 illustrates an alternative method for web-enabling an engineeringtool using XML formatting according to the present invention.

FIG. 8 illustrate web-enabling a legacy engineering tool according tothe present invention using the application interface of the legacytool.

FIG. 9 is a screen view of a web-enabled Flowchart Programmingengineering tool according to the present invention.

FIG. 10 is a screen view of a web-enabled Ladder Logic programmingengineering tool according to the present invention.

FIG. 11 is a flowchart outlining method steps of one embodiment of thepresent invention.

FIG. 12 is a flowchart outlining a method according to the presentinvention for programming a programmable controller.

FIG. 13 illustrates a configuration of a system according to presentinvention, wherein a client device is networked with a server, having aweb-enabled engineering tool, and a second client device networked withthe server is on a LAN with one or more programmable controllers.

FIG. 14 illustrates an alternative configuration of the presentinvention, wherein the programmable controllers are directly interfacedwith a server, having a web-enabled engineering tool, that is incommunication with a client device.

FIG. 15 illustrates yet another alternative configuration of the presentinvention, wherein a server having a web-enabled engineering tool is onthe Internet or an intranet with a client device and one or moreprogrammable controllers are networked with the server over an intranetor the Internet.

FIG. 16 is a flowchart outlining the steps for providing engineeringtool services according to the present invention.

FIG. 17 is a flowchart outlining the steps for generating programmingcode off-line, according to the present invention.

FIG. 18 illustrates a new business paradigm for selling engineering toolservices, according to the present invention.

FIG. 19 illustrates an alternative new business paradigm for sellingengineering tool services, according to the present invention.

FIG. 20 illustrates an embodiment of the present invention whereinhuman-readable engineering code is stored on a server and linked to thecompiled code running on a programmable controller and accessible to anautomation server.

FIG. 21 illustrates how the present invention may be set-up to be in asingle corporate or business entity.

FIG. 22 illustrates a collaborative engineering system according to thepresent invention.

FIG. 23 is a flowchart outlining a method of developing and testingprogramming code for programmable controller and/or configuration data,according to the present invention.

FIG. 24 is a flowchart outlining a method for generating and installingprogramming code on a programmable controller, according to the presentinvention.

FIG. 25 illustrate one embodiment of the present invention wherein anengineering tool set reside on a server, contains a configurationeditor, and is invokable by a client device over a network.

FIG. 26 is a flowchart outlining a collaborative engineering methodenabled by the present invention.

FIG. 27 is a flowchart outlining an alternative collaborativeengineering method according to the present invention.

FIG. 28 is a flowchart outlining another alternative collaborativeengineering method according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention, among other things, provides systems and methodsfor writing programming code (which usually also involves generatingconfiguration data) on a central server and for downloading compiledprogramming code along with any configuration data to a programmablecontroller, such as a PLC. As shown in FIG. 3, a client device 30, suchas a personal computer containing a browser, such as Microsoft InternetExplorer® or Netscape Navigator,® resides on a public or private network35. The network 35 may be the Internet or it may be an intranet. In oneembodiment, a PLC 40, such as Siemens® S7-200 PLC, is connected to theclient device 30 via an interface cable 45, such as Siemens® PC/PPIcable. The cable may contain dipswitches 48 to control settings, such asbaud rate. In this embodiment, the client device 30 acts as aprogramming device 30 for programming the PLC 40. However, unlike priorart approaches to programming the PLC 40 wherein the engineering toolsfor programming the PLC are installed on the programming device, theengineering tools needed to write and compile programming code reside ona server 50 that is accessible by the client device 30 over the Internetor over an intranet or other network 35. The engineering tools arepreferably web-enabled to operate in any browser application on anyclient device 30.

A user 55 accesses the server 50 over the network 35 with the clientdevice 30. The client device 30 may be a thin client, i.e. it need notcontain any software other than a browser. Thus, the client device 30may take many forms including personal computers, web-enabled PDAs, cellphones, Internet ready television devices, and Internet appliances, etc.The present invention is scalable in that it may operate in a variety ofmodes on a variety of client devices having a variety of functionality.For instance, the present invention may operate with limitedfunctionality on a web-enabled cellular phone browser, which has limitedfunctionality and computing ability, or it may operate with robustfunctions on a sophisticated personal computer having a high-speedprocessor and large amounts of memory and robust graphic capabilities.

In accordance with the present invention, engineering tools, similar totools such as Siemens STEP 7,® reside on the server 50 and areweb-enabled. Typically, these engineering tools will employ graphicalprogramming schemes, such as Ladder Logic, Flowchart Programming,Sequential Function Charts, or Function Block Diagrams. (See e.g. FIG.1). Preferably, they are configured to handle a variety of programminglanguages, including Instruction List Programming and all other standardlanguages, such as for example all IEC-1131 standard languages (e.g.,LAD, FBD, SFC, IL and ST). The tools are configured to run in a browserapplication, thus making them operate independently of the operatingsystem employed by the client. Preferably, the engineering tools areconfigured to operated with an HTML or XML interface, so that they canoperate on any available browser. The tools also may provide aconfiguration editor to map a controller's logic I/O area to a physicalI/O area.

FIG. 4 depicts one embodiment of the general system architecture forweb-enabled engineering tools. A web-client device 30 contains astandard web-browser. An engineering tool for generating programmingcode for a programmable controller resides on a web-server 50 and iscapable of operating on the web-client in a browser application. Theengineering tool is web-enabled, and, in its most basic form, itcomprises an editor or editors that may be run on the web-browser.Advantageously, the editors are operating system independent and may runon the latest browser, operating system, and hardware. The web-server 50may also contain an editor for performing hardware configuration. It mayalso contain software and hardware necessary to perform versionmanagement and to run simulations. The web-client 30 and the web-server50 both reside on a network 35, such as an intranet or the Internet. Auser creates programming code and/or generates configuration data for aprogrammable controller on the web-client 30. The code and configurationdata are converted to an XML document and transmitted over the network35 to the web-server 50. Programming code and configuration data may bestored in a project data base 58 associated with the web-server 50. Theproject data base 58 may take the form of any standard storage medium.The server 50 need not be running the latest platform (OS and hardware).

FIG. 5 depicts an alternative embodiment wherein a web service layer 70is incorporated with the server 50. Additional web-services, such assimulation services and tools, may be layered on top of existingengineering tools. This provides the engineering tool developer with aquick and cost effective way to innovate and develop new products. Anengineering tool vendor can leverage and extend the longevity of theirexisting investment in developing the engineering tool. In thisembodiment, users of a basic engineering tool will have at theirdisposal robust engineering services that are only a mouse click away.

XML is particularly well-suited for use with the present inventionbecause graphical representations, such as those used by common PLCprogramming languages, are readily converted to an XLM document. Thus,the transmission between the client 30 and the server 50 is preferablein the form of an XML document.

FIG. 6 illustrates the client-side, server-side and Internet componentsneeded to web-enable a standard engineering tool, such as Siemens STEP7® using Chart Programming Techniques. While Chart ProgrammingTechniques may be used to web-enable standard engineering tools such asSiemens STEP 7,® Microsoft's® .Net technology provides a more efficientmethod for web-enabling engineering tools. As is shown in FIG. 7, .Nettechnology facilitates interfacing a web service application 99 and aweb-server using XML formatting. It also allows for client-server dataexchange in an XML format.

As is shown in FIG. 8, new web services 50 can be build on top of theApplication Interface (“API”) 59 of an existing engineering tool 77,such as Siemens STEP 7®. The server 50 and client devices 30 thenexchange XML documents using standard protocols.

The web-enabled, browser-executable engineering tools preferably haveuser friendly functions for the various phases of an automation project.Screen views depicting a typical web-enabled engineering tool as itwould be viewed on a client device with a standard browser are depictedin FIGS. 9 and 10. FIG. 9 depicts a web-enabled flowchart programmingengineering tool and FIG. 10 depicts a web-enabled engineering tool forprogramming in a Ladder Logic scheme. Typically, these engineering toolsinclude functions, such as configuration and parameterization ofhardware; definition of communication;

programming; testing, start-up and servicing; documentation andarchiving; and operating/diagnostics. The tools may also contain asymbols editor for defining symbolic designations, data types, andcomments of global tag. The tools preferably support all programminglanguages, including but not limited to flowchart programming, IL, ST,SFC, LAD, and/or FBD, and all subsequent programming languages specifiedby IEC.

As discussed above, the functions provided by the engineering tools maybe scalable depending upon the type of client device they will run on.For example, a very thin client device, such as a web-enabled cellularphone, may only be able to run a tool that uses text based or limitedgraphical editing functions. A more sophisticated client device, such asan IBM 600E Thinkpad,® can support more functions and can in turn allowthe engineering tool to perform more functions, such as full graphicalediting during code development. Thus, in accordance with the presentinvention, whether the engineering tool functions are perform on theclient device or on the server side, may vary depending upon thecapabilities of the client device, the speed of the Internet or intranetconnection, and other parameters.

As is shown in FIG. 3 and outlined in this flowchart of FIG. 11, in oneembodiment of the present invention, a user (or several users) mayaccess a PLC programming engineering tool 38 (or an engineering tool forprogramming other programmable controllers) that resides on a server 50,step 1000. In one embodiment, the server 50 resides on the World WideWeb portion of the Internet. In another embodiment, the server resideson a private corporate network or a corporate intranet. The user 55operates the engineering tool 38 on a web browser on the client device30, step 1005, and creates programming code on the browser for theprogrammable controller, step 1010. Standard security measures may beemployed to limit access to both the server and to the programs createdthereon. The user 55 may create a program in a single session or over aperiod of several sessions. The user may modify, edit, and debug theprogramming code in a browser application, step 1015. The code generatedon the browser may be in graphical form. The code is then converted to adocument, step 1020 and the document is transmitted over the network tothe server, step 1025. Preferably, the programming code is stored on theserver 50, step 1030.

Editing software, debugging software and a compiler may be located onthe server 50. This allows virtually any PC, PDA, or other web-enabledclient device 30 to act as a programming device. After the user 55creates and edits the programming code, the code may be stored andcompiled on the server 50, which preferably has a compiler. In someembodiments, an additional server could be used to archive the code.Moreover, the compiler may also reside on a different server that isaccessible to the server containing the engineering tool.

After the code is created, debugged, and compiled, it is downloaded to aprogrammable controller. As is shown in the flowchart of FIG. 12, in oneembodiment programming a programmable controller comprises two steps:establishing communication between the controller and the server, step2000, and downloading the programming code to the controller over thenetwork, step 2005. In one embodiment, such as the one shown in FIG. 3,the code may be downloaded to the client device 30 which in turn maythen be interfaced with the programmable controller 40. In thisembodiment, a copy of the compiled programming code may reside on theclient device or be archived on the client device.

Typically the client device 30 is interfaced with the programmablecontroller 40 via a connector cable 45, such as Siemens PC/PPI ConnectorCable (see FIG. 3). As is shown in FIG. 3, when a PC is used as theclient device 30 the connector cable allows a serial interface on theprogrammable controller to communicate with a standard RS-232 serialinterface. When another device, such as a PDA, is used as the clientdevice, the connector cable interfaces with a communication port on thedevice. The cable may, as is shown in FIG. 3, contain DIP switches 48that are used to select an appropriate speed (baud rate) at whichinformation is passed between the PLC 40 and the client device 30. Theclient device 30 may, as is shown in FIG. 13, be interfaced with aplurality of programmable controllers 40. In some embodiments, wherethere are a large number of programmable controllers interfaced with asingle client device a repeater (not shown) may be needed in conjunctionwith the cable.

In an alternative embodiment, such as the one shown in FIG. 14, theprogrammable controllers 40 may be directly or indirectly connected to anetwork, such as a LAN 100, on which the server resides without havingto go through the client device 30. In this embodiment, the programmablecontrollers 40 are in communication with the server 50 over thenetworks, 100 which may comprise a standard network usingTCP/IP-ethernet protocols, a Profibus® network, or virtually any othernetwork configuration. The compiled programming code may be thendownloaded directly to a programmable controller 40.

In yet another embodiment, such as the one depicted in FIG. 15, theprogrammable controllers 40 may communicate with the server 50 over anetwork, 110 such as an intranet or the Internet. The programmabledevices may, in some embodiments be linked together on a LAN 100 usingprotocols such as TCP/IP or Profibus® or any other appropriate protocol.

Regardless of whether the programmable device is directly interfacedwith the network where the server resides or is in communication withthe server through a client device, an archival copy of the programmingcode may be stored in an archival project database 120 on the server 50or on a memory device associated with the server 50. (See FIG. 14). Thisadvantageously provides centralized storage for back-up copies of thecompiled programming code. The archival copy may also be stored on aseparate server or in a database available over the network.

In some embodiments it may be desirable to create the programming codefor the programmable controller off-line, i.e. after the client deviceis disconnected from the server containing the engineering tool.Off-line programming allows a user to create and edit the program codewithout maintaining a connection with the server. As is outlined in theflowchart of FIG. 17, a user establishes communication between a clientdevice and a server containing a web-enabled engineering tool and adatabase of programming projects, step 3000. The user then opens theweb-enabled engineering tool in a browser application on the client3005. The user then checks out a copy of the project from the projectdata base, step 3010 and the copy of the project is transmitted to theclient device, 3015. Communication between the client and server is thenterminated, step 3020. The user is now free to edit the checked-out copyoff-line, step 3025. When the user is finished editing, the userreestablishes communication between the client and server, step 3030.The edited programming code is then checked back in 3035, and may beaccessed by other users who have access rights. In some embodiments,while the project is checked out, other users may be permitted to read acopy of the checked out project in the form it existed prior to beingchecked out. Depending upon the sophistication and resources of theclient device, off-line programming techniques and functions may vary.

Where the client device lacks sophistication, a simple text basededit-only function may be provided. Where the client resource containshigher levels of sophistication (e.g., memory, graphics capability,processor speed, etc.) more sophisticated graphical editing/codecreation functions may be provided. Thus, the present invention isscalable. For example, in one embodiment operating on a simpleweb-enabled device the user may be provided with only a text editingfunction, while in an other embodiment operating on a more sophisticatedclient, the user may be provided with an engineering tool that operatesin the web-browser that contains all the graphical editing functionsthat exist when the user is connected to the server.

In addition to depending on client resources (e.g., memory), otherfactors, such as the client operating system and security issues, mayimpact the functionality of the web-enabled engineering tool. In orderto work off-line, the operating system of the device needs to supportsome way of installing the application on the client device. This isgenerally not an issue with modern PDAs, but may be an issue withsmaller appliances, such as cellular phones. For security reasons, webbrowser applications are generally restricted from accessing systemresources, such as drives and system memory. Microsoft Corp., RedmondWash., provides software for allowing applications running on itsInternet Explorer® to access client side system resources by means ofACTIVEX controls embedded in the application. For those wanting bettersecurity, Microsoft Corp. provides the user with the ability in itsbrowser to disable downloading of ACTIVEX controls altogether, or onlyaccept downloads from trusted sites or only originally signed ACTIVEXcontrols.

In one embodiment, specific functions are provided to the client deviceon an as-needed basis. For example, syntax checking is not provideduntil the user of the client device needs that function. This enablesthe user to download to the client device minimal functions initiallyand to add additional functions only when those functions are needed.

In general, the programmable device does not need to be connected to theprogrammable controller when programming code is being generated andcompiled. However, in some embodiments it may be desirable to have theprogrammable controller on-line with the server and the client device atthe same time. In this embodiment, changes are downloaded to theprogrammable controller. In addition, status of input and outputelements can be monitored. In some embodiments the server may beequipped with diagnostic software or functions that allow for monitoringof the programmable controller. In yet other embodiments, the server cansimulate inputs and outputs and communicate these with the programmablecontroller. This allows for diverse and robust testing algorithms to becreated and stored centrally. In some embodiments, the robust testalgorithms may be accessible only by authorized users and the users maybe charged a fee for their use.

The present invention provides a new paradigm in the engineering toolindustry. Prior to the present invention, engineering tools wereproducts that were manufactured and sold (See FIG. 2). In accordancewith the present invention, web-enabled engineering tools provide a newbusiness paradigm where the manufacturer of an engineering tool providesa service. (See FIGS. 18 & 19). In one embodiment, such as the oneoutlined by the flowchart of FIG. 18, a user is provided access to theserver containing an engineering tool for developing and compilingprogramming code for a programmable controller, step 200. The user maybe provided free access to the engineering tool for the purpose ofwriting programming code. The user can develop the code on a clientdevice that communicates with the server, step 205. The user can createand modify programming code without being charged a fee. Thisadvantageously provides even small business concerns with access tosophisticated and up-to-date engineering tools. Only after the usercompletes the code and compiles it is a charge incurred, step 207. Insome embodiments, the charge is calculated at the time the programmingcode is compiled. In another embodiment, the user is charged upondownloading the compiled code to a PLC. (See FIG. 19, step 220). Thecharge for the code may be based on the size of the compiled code, thetime required to write the code, the number of inputs and/or outputs thecode is designed to handle, or a variety of other parameters that may bemeasured. Since the engineering tool resides on a central server and noton a client device, limiting and controlling access to the tool issimplified. Moreover, it is a simple matter for a customer servicerepresentative or salesperson to provide a customer with additional useof the programming tool where such additional use would be advantageousfrom a business prospective. For example, a salesperson might provide alimited period of free use of a web-enabled engineering tool forprogramming and configuring a PLC when a customer purchases a new PLC ornew field device that interfaces with an existing PLC.

Viewed from the perspective of the entity building and/or supplyingengineering tools, the new business paradigm may take the form of thesteps outlined in the flowchart of FIG. 16. The tool manufacturer orprovider maintains a web-enabled engineering tool on a server that isaccessible to clients over a network, such as the Internet, step 1601.Clients are provided access to the tool over the network, step 1605. Insome embodiments, passwords or other security measures may be used torestrict access to only authorized users; while in other embodiments thepublic may have access to the tool, but not necessarily access to thecode created with the tool. In accordance with this embodiment, theengineering tool provider receives a document, e.g., over a network,from a user that contains programming code that was generated with theweb-enabled engineering tool, step 1610. The programming code may thenbe compiled, step 1615, or it might be saved and made accessible to theentity that created it or to an entity authorized to access it.Eventually, the code is compiled and then downloaded to a programmablecontroller, step 1620.

Since the code is created on a central server, the code may be archived

in both human-readable form and in compiled form (see FIG. 20). Thisprovides a method to reinstall existing software on new programmablecontrollers or to restore old versions of code when a new version failsto perform in a desired manner. In one embodiment, the user is charged afee for obtaining downloading an archived copy. This fee may be lowerthan the initial fee for the first copy downloaded to the user.

Moreover, since in some embodiments, the human-readable form of the code(also known as source) is archived and linked with the machine readablecode, web-enabled monitoring, simulation, and control of automatedfacilities is facilitated. For example, as is shown in FIG. 20 aweb-enabled PLC 300 may contain an embedded webserver 310. The PLC maybe connected to a network 350, such as the Internet or an intranet. ThePLC may be programmed with the web-enabled engineering tools of thepresent invention. The programming code for the PLC may reside on anengineering server 400 in both human-readable form and in compiled form.The human-readable form is stored in a memory or data storage device 410and the code is linked to the compiled form that also resides in amemory device 420 associated with the engineering server. Since theengineering server is accessible over the Internet or an intranet alongwith the PLC, it is possible to maintain another server (either a serverphysically separate from the engineering server or a virtual server,which is physically part of the engineering server or the PLC), such asan automation server on the same network. The automation server may evenbe part of the PLC, such as when the PLC contains an embeddedweb-server. Sophisticated and robust simulation, monitoring and controlsoftware may reside on the automation server and be web-enabled to beaccessed by a client device on the Internet or intranet. Since thehuman-readable version of the programming code for the software runningon the PLC is available via the engineering server, robust simulation,diagnostic, control, and monitoring software packages may advantageouslyaccess the human-readable code and provide valuable information forrunning these software packages. For example, since the human-readablecode is readily accessible, accessing tag information for various fielddevices controlled by the PLC is facilitated. The present invention thusenables sophisticated and robust communication and data transfer from ashop floor to a board room.

As is shown FIG. 5, maintaining a server with centralized web-enabledengineering tools provides a platform for the developer of theengineering tool to launch new services and products. For example, priorto the present invention, the cost of purchasing simulation tools foroptimizing programming code prohibited many customers from investing inthese tools. Since, in one embodiment, the programming code is storedand generated on a central server that is accessible by a large numbersof customers, the cost of installing simulation software on the servercan be spread over this large number of customers. Moreover, in oneembodiment, customers only pay for the use of the simulation tools. Inaddition, diagnostic tools could be installed on the server and sharedin a like manner. In some embodiments, the owner of the server and toolscould be compensated based on usage, based on savings to the customers,or a variety of other schemes.

Because the tools are centrally located, licensing of the tools issimplified. The tools may be licensed to companies, certain individualswithin a company, or individuals themselves. Access to the tools may beaccomplished using encryption techniques and/or password protection andcan be conditioned upon maintaining a valid license. In someembodiments, it may be desirable to provide a limited period of freeaccess to the tool. In some cases, the amount of free access can be tiedto the purchase of programmable controllers. Providing an on-site serverfree of charge for a limited period may also be useful in selling longterm leases of servers to customers. In this embodiment, the user isprovided with the server for a limited free trial period.

In an alternative embodiment, such as the one shown in FIG. 21, acompany may choose to lease or own its own server. For some largemanufacturing companies and/or other entities where security is a majorconcern, limiting access to the server to only the companies' employeesmay be advantageous. Because the engineering tool resides on the serverand not each user's PC, version management, updating and other softwaremaintenance tasks are simplified. Moreover, the engineering tool isoperating independently of the operating system on the user'sprogramming devices. Because the server is accessible to only thecompanies employees, proprietary information may be stored on the serverand accessed by a programming team working at different locations.

The present invention also advantageously provides a system and methodfor collaborative engineering. In one embodiment, multiple users mayaccess and develop jointly the programming code for one or moreprogrammable controllers. As is shown in FIG. 22, a plurality of usersmay access a server. A web-enabled engineering tool 2200 resides on theserver 50 and is capable of running in a browser application on theclient devices 30. The server may contain a memory for storingengineering projects in a database 2210 as well as a configurationmanager 2220. The projects stored in the project database 2210 may bediscrete projects or they may be related. Typically, the user thatcreated a particular project or piece of code is granted full read andwrite rights to that project. As shown in FIG. 22, a first user 5000 mayaccess a first project 2241. Upon accessing the first project 2241,which is typically a document storing programming code in a humanreadable form, an active copy 2250 of the first project is created onthe server 50. With the aid of the web-enabled engineering tool 2200,the first user 5000 may modify the active copy of the first project2250. Other users 5001, 5002, 5003 on the system, may need to view acopy of project 1. This is quite often the case when a second and thirduser are working on related projects. Since an active copy is work inprogress it is possible that the first user 5000 may never save thechanges the first user 5000 is making to the active copy, it would nottypically not be advantageous to grant the second and third users rightsto read the active copy. Instead, it is often preferable to grant thesecond and third users 5002, 5003 read rights to the archived copyresiding on the project database. In some embodiments, it may beadvantageous to provide a fourth user 5001 with either read rights orread-write rights to the active copy. This may be particularly usefulwhere the fourth user 5001 is a customer service representative, aconsultant or supervisor overseeing of the users. Access to the archivedcopies of the projects stored in the database as well as access to theactive copy are generally controlled by a configuration manager. In anembodiment of the present invention, the creator of a project grantsrights to other users through the configuration manager 2220. Often atleast one other user, such as a supervisor or IT administrator, has theability to grant rights.

In one embodiment, such as the one depicted in FIG. 22, a largeprogramming task is divided into several smaller projects. Each projectis stored as a document in the projects database. Each user is primarilyresponsible for a separate project. The first user 5000, for example, isin charge of project 1 2241. Thus, the first user 5000, via theconfiguration manager, is granted read and write rights to the firstproject 2241. Other users, such as the second and third users 5002, 5003may be in charge of separate projects or related projects and are thusgranted lesser rights to project 1, such as read only rights. The seconduser 5002 is tasked with creating project 2 2242 and is thus grantedfull rights to project 2, but users 1 and 3 are given only read-rightsto an archived copy of project 2. User 3 5003 is tasked with creatingproject 3 2243 and is thus granted read-write rights to project 3 butread-only rights to archived copies of projects 1 and 2. Likewise, thefirst user 5000 is granted read-only rights to archived copies ofprojects 2 and 3. A project supervisor, such as the fourth user 5001,may be given supervisory rights, which may include the right to read andwrite to active copies, as well as archived copies, the right to combinevarious projects (either the active copies or the archived copies, intoone piece of programming code, the right to compile the programmingcode, and any other rights needed to oversee a programming project.

The present invention therefore enables numerous methods forcollaboratively programming programmable controllers and generatingconfiguration data for I/O networks and devices, which is usually partof the programming process. FIG. 26-28, outline a few examples of someof the many collaborative engineering methods and techniques enabled bythe present invention. While specific examples are shown in thesedrawings, the method steps that are outline here are intended to beillustrative and not exhaustive of the broad and robust collaborativeengineering methods enabled by the present invention.

The present invention also provides for convenient archiving ofprogramming code and version management. A version manager or versionmanagement system may be incorporated into the configuration manager orcontrolled by the configuration manager. Before new compiled programmingcode is downloaded to a programmable controller (either directly fromthe server to the controller or from the server to the controller viathe client device), a copy of the existing code is archived on theserver. In some embodiments, the programming code is archived in ahuman-readable form before it is compiled. The compiled code andhuman-readable code may be linked together so that the human readablecode may be accessed based on the compiled code. (See e.g. FIG. 20).

A version management tool residing on the server would provide severaladvantages and provide a new business model for engineering toolsuppliers. One of the many advantages it provides is that a customer maysearch for a specific change to a program or may compare two versions ofa program. This is highly desirable in industries regulated by the Foodand Drug Administration (“FDA”). For example, in a food plant the FDArequires that all changes to a PLC program be documented. A versionmanagement tool may provide this functionality. In some embodiments, theversion management tool is part of a configuration manager and resideson a server with an engineering tool. In a typical scenario, a usermakes a change to a PLC program (e.g. version 1.0), for example toincrease the amount of sugar in a mix. The modified program along withthe documentation is saved as a new version (e.g. version 1.1) on theserver. If at some later point in time, it is determined that theproduct is too sweet, a subsequent user can correct this by searchingfor changes to the PLC that affected the sweetness or the quantity ofsugar added to the product. The version manager preferably supports thisfunctionality. Often, it is not possible to revert to the originalversion (e.g. 1.0) because there have been subsequent changes, but theuser can create a new version by making changes to the existing versionrunning on the PLC.

In addition to providing searching functions, the version managementtool may also provide comparing functions that allow a user to compareone version to another to show changes. The compare function may work inboth graphical and text based programming languages and preferablyhighlights the changes.

The present invention also provides a method and system for testingprogramming code developed on a central server. As is shown and outlinedin FIG. 23, a server containing an engineering tool is accessed with aclient device, step 9900. The engineering tool is then operated on theclient device, step 9905, preferably in a browser application on theclient device, and programming code is then created on the server, step9910. The programming code may then be tested by running simulationsoftware on the server, step 9915. The simulation software may mimic anactual programmable controller. In other embodiments, the server may beinterfaced with a testing programmable controller, step 9920.Preferably, the testing programmable controller is configured to testprogramming code and/or configuration data generated with theengineering tool on the server. After the programming code is tested, itmay be downloaded to an actual programmable controller, step 9925, whichis often referred to as the target programmable controller.

One method of downloading code generated by the present invention isoutline in FIG. 24. Programming code and/or configuration data isgenerated on a server, step 9000. The code is then compiled, step 9005.It is then downloaded to a client device, step 9010. And copied to astorage device that is associated with the client device, step 9015. Thestorage device may take many forms and may be a removable storagedevice, such as a disk drive or flash memory unit. The storage devicemay be interfaced or communicatively coupled with an electronic device,step 9020. The code may then be copied to the electronic device, step9025. From the electronic device, the code may then be downloaded to atarget programmable controller, step 9030.

As is shown in FIG. 25, the present invention may also comprise aconfiguration editor 9100 for generating code or data for configuringI/O networks and devices that resides on a server 9200. A configurationeditor usually part of the engineering tool 9300 or part of anengineering tool set 9350. Those skilled in the art will recognize thatin most cases the engineering tools described herein may contain aconfiguration editor and the generating of programming code may comprisethe generation of configuration data. The configuration editor may takemay forms, but is usually graphical and is preferably adapted to beinvokable by a client device 9500 over a network 9600, such as theinternet. A graphical configuration editor may show the topology of anI/O network and the device on the network. Configuration data for I/Onetworks and devices is typically downloaded to a programmablecontroller 9700 on the network. In some cases, the data may bedownloaded to intelligent devices on the network. Configuration dataoften comprise information such as baud rates and information relatingto the mapping of logical to physical I/O.

The present invention, although described above with reference tospecific embodiments, may be embodied in numerous forms, too many todescribe herein, and should not be limited by the above describedexemplary embodiments, which are illustrative of the present invention,but not exhaustive. For example, those skilled in the art will alsorecognize that although the method steps of the present invention arediscussed above in a specific order, it is often the case that the orderof the steps is not critical and the invention may be practiced byperforming the steps in differing order. For example, it is oftenimmaterial to the practice of the present invention whether the methodsteps are performed in any particular order. For example, it makes nodifference if value is conveyed by a customer before or afterdownloading compiled code and configuration data to a PLC from a centralserver.

1. A system for configuring I/O networks and devices comprising: aserver communicatively coupled to a network; and a configuration editorresiding on the server, the configuration editor adapted to be invokableby a client device that is communicatively coupled to the network, theconfiguration editor adapted to map a logical I/O area of a programmablelogic controller to a physical I/O area of the programmable logiccontroller, the programmable logic controller controlled via programmingcode adapted to cause the programmable logic controller to controlfield-based actuators, the configuration editor comprised by anengineering tool adapted to create an XML version of the programmingcode, the engineering tool residing on the server.
 2. The system ofclaim 1, wherein the network is the Internet.
 3. The system of claim 2,further comprising the engineering tool for developing the programmingcode for the programmable logic controller.
 4. The system of claim 1,wherein the client device comprises a personal computer.
 5. The systemof claim 1, wherein the client device comprises a PDA.
 6. The system ofclaim 1, wherein the client device comprises a cellular telephone. 7.The system of claim 1, further comprising a version management tool thatresides on the server.
 8. The system of claim 7, wherein the versionmanagement tool is part of a configuration manager.
 9. The system ofclaim 1, further comprising a version management tool for managingversions of the programming code for the programmable logic controller,the server having the version management tool installed thereon, theversion management tool invokable by the client device over the network,and a plurality of versions of the programming code residing on theserver.
 10. The system of claim 9, wherein the version management toolis part of a configuration manager that resides on the server.
 11. Thesystem of claim 9, wherein the version management tool comprises anapplication for searching for versions having predetermined attributes.12. The system of claim 9, wherein the version management tool comprisesan application for comparing two or more versions, of the plurality ofversions of the programming code, with each other to show differencesbetween the two or more versions.
 13. The system of claim 9, furthercomprising the engineering tool residing on the server, the engineeringtool configured to run on the client device in anetwork-interfacing-application.
 14. The system of claim 13, wherein thenetwork-interfacing-application comprises a web-browser and the networkis the Internet.